Vacuum-pump.



G. S. WILLIAMS.

VACUUM PUMP. Arrmomron FILED mum, 1909.

Patented June 7, 1910.

2 SHEETS-SHEET 1.

511m Mon ANDREW E GRAHAM c0. Pnow-LnkoeiAPdEfls. WASHINGTON 04a G. S.WILLIAMS.

VACUUM PUMP.

APPLICATION FILED MAR. 2, 1909.

Patented June 7, 1910.

TU mm a 2 M m I. i T w/ m M H m M s E 8 n W s 2 0 a 5 Mlik WitnessesUNITE TAT A anon.

GEORGE S. WILLIAMS, OF NORFOLK, VIRGINIA, ASSIGNOR TO AMERICAN PIANOPLAYER COMPANY, OF NORFOLK, VIRGINIA, A CORPORATION OF VIRGINIA.

VACUUM-PUMP.

T 0 all whom it may concern:

Be it known that I, GEORGE S. VVILLIAMs, a citizen of the United States,residing at Norfolk, in the county of Norfolk and State of Virginia,have invented new and useful Improvements in Vacuum-Pumps, of which thefollowing is a specification.

My invention relates to improvements in exhaust pump apparatus, and isespecially adapted for use in pneumatic players.

In pneumatic playing mechanism it is desirable that the vacuum chamberthat is subjected to the venting effect to provide move ments of thepneumatic mechanism, be subjected to the action of a second or auxiliaryvacuum chamber which acts to immediately overcome the changed conditionsin the first chamber produced by the venting action, the auxiliarychamber thereby serving as a vacuum controlling device for the firstchamber, and having its vacuum in turn produced by an exhaust mechanismsuch as a pump or bellows mechanism. Owing to the requirements, theauxiliary chamber is relatively large and therefore requires the use ofan exhaust mechanism of suificient power to maintain the desired vacuumtherein. To obtain this result without producing variations in thedegree of vacuum in such chamber, and at the same time provide anapparatus which can be readily positioned and inclosed within the caseof a piano or other player, is the aim of the present invention.

The main object of my invention is to provide an exhaust mechanism whichwill provide a constant exhausting relation to the auxiliary chamber.

A further object is to provide an apparatus by means of which a vacuummay be quickly produced in a relatively large chamber and maintainedtherein by the use of a relatively small and compact apparatus,requiring a minimum amount of power.

A further object is to provide an exhaust pump apparatus having aplurality of pistons arranged in tandem and each operating to affect thecondition of a chamber subjected to the action of all of the pistons.

A further object is the provision of a plurality of piston cylindersarranged in tandem, said cylinders having walls forming conduits, theconduits having valved connection with the cylinders.

To these and other ends, the nature of Specification of Letters Patent.

Application filed March 2, 1909.

Patented June *7, 1910.

Serial No. 480,885.

which will be readily understood as the invention is hereinafterdisclosed, my invention consists in the improved construction andcombination of parts hereinafter fully described, illustrated in theaccompanying drawings, and particularly pointed out in the appendedclaims.

In the accompanying drawings, in which similar reference charactersindicate similar parts in each of the views,Figure 1 is a verticalsectional view of an exhaust pump mechanism illustrating one form of myinvention, some of the parts being shown in elevation. Fig. 2 is ahorizontal sectional view of the construction shown in Fig. 1. Fig. 3 isa vertical cross-sectional view. Fig. 1 is a detail view of one of thevalves shown in Fig. 1. Fig.5 is a view similar to Fig. 1, but showing amodified form of construction. Fig. 6 is a view similar to Fig. 2, butshowing the construction illustrated in Fig. 5. Fig. 7 is a verticalcrosssectional view of the mechanism shown in Fig. 5.

10 designates a support for the exhaust pump mechanism, which supportmay be of any desired form or type, or may form a portion of thestructure of the chamber being exhausted, as desired. I have shown thepump mechanism as secured to the underside of the support, but it is tobe understood that this may be varied to provide the supportingconnection at points other than the top, the latter construction beingshown as it indicates one manner in which the mechanism may be mountedwithin the casing without liability of disarrangement of parts oraffecting the operation of the mechanism.

11 designates a casing of any desired cross-sectional configuration,that shown in Figs. 1 and 3 being wholly angular, while that shown inFigs. 5 to 7 provides a semicylindrical construction. It will be obviousthat still further changes in the cross-sectional configuration may bemade without materially varying the operation of the mechanism.

Referring first to the construction shown in Figs. 1 and a of thedrawings, the casing 11, which is long and relatively narrow, has itsupper wall in the form of a conduit 12 extending substantially thelength of the casing, and having an opening or port 13 in communicationwith the chamber to be exhausted, the latter and the particularconnections leading thereto not being shown. In this form ofconstruction the cylinders have their bores angular (square orrectangular, as desired), in cross-section, and hence the side walls 14,which are solid, eX- tend in the same plane throughout their verticallength, the inner face of the upper and side walls forming thecorresponding surfaces of the cylinders. The bottom 15, which completesthe cross-sectional configuration of the casing, is of particular formand will be hereinafter described in detail.

The casing 11 has its outer end closed by a hollow head 16 which is inopen communication with the conduit 12, and at suitable points in thelength of the casing partitions 17 are provided, each of said partitionsalso being hollow and each being in open communication with said conduit12. In the drawings, two partitions 17 are shown, providing, with theend 16 three cylinders, the inner one of which has its inner end open,said latter cylinder being of less length than the remaining cylinders.By this construction, it will be seen that one wall (the upper) of allof the cylinders is hollow, and that the outer end of each cylinder isalso hollow, these walls each forming conduits. It will also beunderstood that while the end 16 and partitions 17 are shown anddescribed as independent structures, they are, in effect, equivalentstructures with respect to the cylinders, since they form a hollow headfor the cylinder located in rear of the head.

The conduit in the end 16 is in communication with the outer cylinderthrough an opening 18, normally closed by a valve 19, said valve beingmovable, under the action of the piston mounted within the cylinder, toprovide open communication between the end conduit and the cylinder. Therear walls of the conduits of the partitions 17 are each formed withopenings 18 and valves 19 operating in the same manner in each cylinder.

20 designates the pistons, one of which is located in each cylinder.Each piston is in the form of a block 21 having a facial area less thanthe cross-sectional area of the cylinder, the block having peripheralpacking 22 of less thickness than the space bet-ween the edges of thepiston and the opposing wall of the cylinder. The packing 22 may be ofany desired character, that shown in the drawing being in the form of afacing of leather secured to the front face of the block and havingprojecting edges extending rearwardly into the space between the edgesof the block and the cylinder wall, the leather being sufiiciently stiffto cause its free edges to ride in contact with the walls of thecylinder and prevent misplacing of such edges under the pressures ofair; it will be understood that such packing may, instead of being of asingle piece of leather, be in the form of strips secured to the frontface of the piston. Each piston is provided with one or more openings 23extending therethrough and through the leather facing (if the latter iscoextensive with the face of the piston) each opening being controlledby a valve 24 located on the rear side of the piston. The valves 24: maybe of any desired type, those shown in the drawings being similar inconstruction to the valves 19.

The pistons 20 are operated by means of arms 25 mounted on the cranks ofa crank shaft 26 supported in suitable manner, as by brackets 27,in'rear of the casing 11, the front ends of the arms 25 being connectedby suitable angular connections 28, with the rear of the pistons. Eachpiston has a separate arm 25, and as the cranks are arranged angularwith respect to each other on the crankshaft, the movements of the shaftwill cause simultaneous movements of the pistons. These movements,however, while of the same length within the cylinders, are timed so asto prevent any two pistons from reaching the same extreme of itsmovement at the same time, this result being obtained by the angularityof the cranks. To permit the pistons to be connected to their operatingarms by the brackets 27, the bottom 15 is slotted in each cylinder as at28, the length of the slots being sufficient to permit of the fulllength of movement of the piston and its bracket. The length of the slotin the rear cylinder is less than that in the remaining cylinders, butthe distance between the forward end of the cylinders and the forwardend of the slots is the same in all of the cylinders; as the slots 28open to the outside of the cylinder, the movement of the pistonsrearwardly is limited to a point forward of such forward end of theslot, the length of movement of the pistons being therefore the same.

Owing to the arrangement of the valves 19 and 24, it will be understoodthat when a piston is moving toward the left in Fig. 1, the pressureahead of the piston will seat the valve 19 and open the valve 24 of thepiston, thereby permitting the air to escape to the rear of the piston;when, however, the piston reaches the end of its forward stroke andbegins its return movement, the valve 24 immediately closes, whereuponthe movement of the piston opens valve 19 by reason of the reduction ofpressure of the rear side of said valve, thereby placing the cylinder incommunication with the exhaust chamber through conduit 12.

The valve structure shown in Fig. 4 comprises a block 29 having a facing80 of suitable material, and provided with one or more bails 81, saidbails being adapted to be supported to permit a swinging movement of thevalve, in ears 32 carried by the cylinder head and the piston. This formof valve is one type which may be used in the apparatus, its cheapness,the simplicity of operation, and the elimination of springs, making itdesirable where a relatively low cost apparatus is employed. It will beunderstood, however, that any other form of valve may be employed forthis purpose. The crank-shaft is operated from a suitable motor (notshown), said shaft having a pulley 33 by means of which connection maybe made with the motor.

As heretofore pointed out, one of the principal objects of the presentinvention is to provide a constant exhausting relation with the vacuumchamber, and this is provided by the particular arrangement of the partsheretofore described, as will be understood from the following:Designating the three cylinders shown, as A, B, and C, for the purposesof illustration, and with the parts in the position shown in Figs. 1 and2, and the crank-shaft revolving in the direction of the arrow'shown inFig. 1,the piston in cylinder B is on the point of changing from itsforward to its return stroke; piston in cylinder A is on itsreturnstroke and acting as the exhausting piston, while the piston incylinder C is on its forward stroke. As the shaft revolves, the pistonin cylinder B will begin its return stroke thereby opening communicationwith the vacuum chamber, the length of movement of this piston prior toopening such communication being approximately that required to completethe exhausting stroke of the piston in cylinder A, so that as the latterpiston is about becoming inoperative for exhausting purpose, its work istaken up by the piston in cylinder B. The latter continues as the soleexhausting piston until it reaches the position in which the piston incylinder A is shown, at which time the piston in cylinder C has reachedthe end of the forward stroke, and begins the movement to place it inposition to act as the active exhausting piston. From this it will beunderstood that at least one of the cylinders is in active communicationwith the vacuum chamber at all times; and that such exhausting action isplaced not only on the vacuum chamber, but also on the conduits in theheads of the other cylinders so that the valves of the inactivecylinders are positively held to their seats by difference in pressureuntil the pressure in an inactive cylinder is reduced to a point belowthat within the conduits, so that a surety is had that the vacuumpressure in a cylinder is at least that in the conduits before thecylinder is brought into activity. This feature permits of a regulationof vacuum pressure, by placing 1n the bottom of each cylinder a port 40normally closed by a member 41 having ports 42, said member having areciprocating movement to open or close the port 40, the movement of themember being controlled by any suitable regulator connected with thevacuum chamber, it being obvious that if the ports 40 and A2 are broughtinto alinement, the movement of the piston will not sufficiently affectthe pressure in the cylinder to cause the valve 19 to open, the lengthof time such alinement is had deter mining the length of activity of thepiston as an exhausting means; and by reason of the movements of themember 11, variations in pressure within the cylinder can be had duringthe period of movement of a single piston, sufficient to balance thegreater or less venting of the first chamber in cases where a greater orless number of notes are sounded at the same time, the varying of thesize of the vent produced by the ports 10 and 42 producing correspondingvariations in pressure in the cylinder.

As shown, in Fig. 2 the arms 25 are spaced apart horizontally, therebyrequiring that the slots 28 in the cylinders be out of longitudinalalinement. In order that the mechanism may be positioned within the caseof the piano without liability of obstructing the exhaust from thecylinders, through the slots 28, the arm 25 for the open ended cylinderC is located on the side of the mechanism closest to the interiormechanism of the piano, since the exhaust from this cylinder may passout through its open end; to permit the remaining cylinders to exhauston the same longitudinal plane, the slot 28 for the intermediate bracket27 is extended laterally, as at 28 as shown in Fig. 2.

lVhile I have shown the number of cylinders as three, it is to beunderstood that the number may be varied; but whatever the number ofcylinders and pistons used, the cranks will be angular with respect toeach other and spaced apart distances sutlicient to cause the pistonmovements to provide a continuous exhausting relation to the vacu umnormally uniform in pressure degree, variations being provided by thecontrolling mechanism such, for instance, as that provided by ports 40and 42.

The structure shown in Figs. 1 to at is especially adapted to be madefrom different materials, such as metal or wood; when made from thelatter material the cost is greatly reduced without affecting theoperation and durability of construction.

The construction shown in 5 to 7 differs from that shown in Figs. 1 tot, mainly in the fact that the sides and botton'i of the casing areeliminated, the piston cyl inders being tubular in form andscrewthreaded to the hollow heads, as shown, the material in this formbeing metallic. To

permit the parts to be readily cast, the upper Wall of the conduit 12 isin the form of a plate 4A bolted to the remaining portions of thecasing, the heads of the cylinders, as shown in Fig. 7, beingsemi-cylindrical. In this form, the cylinders are of equal length, andthe pistons are provided with a slightly different form of packing; andthe valves are shown as of a different type, but these changes aresimply in details of construction without changing the mode of operationwhich is the same as in the form previously described.

Having now described my invention, pointing out one or more forms inwhich the same may be provided, but without showing in detail all of thevarious changes and modifications therein which may be used to producethe desired result, what I claim as new is:

1. The combination with a vacuum chamber, of exhausting mechanismtherefor, said mechanism comprising a plurality of cylinders arranged intandem, said cylinders each having a head formed with a conduit in opencommunication with said chamber, each head having an opening leading toits cylinder, valves carried by said heads for controlling saidopenings, and valved reciprocating pistons mounted within the cylinders,the reciprocations of the pistons providing intermediate periods ofexhaust pressure producing activity within its cylinder, said pistonshaving relative move ments to combinedly provide a constantexhaust-pressure on the chamber of substantially uniform degree.

2. The combination with a vacuum chamber, of exhausting mechanismtherefor, said mechanism coniprising a plurality of cylinders arrangedin tandem, said cylinders each having a head formed with a conduit inopen communication with said chamber, each head having an openingleading to its cylinder, valves carried by said heads for controllingsaid openings, and valved reciprocating pistons mounted within thecylinders, the reciprocations of the pistons providing intermediateperiods of exhaustpressure producing activity within its cylinder, saidpistons having movements of uniform length and timed to combinedlyprovide a constant exhaust-pressure on the chamber of substantiallyuniform degree.

3. In combination, a casing having a conduit, cylinder heads each havinga conduit in open communication with the casing eonduit, a cylinder foreach head and in controlled communication with the conduit in the head,said cylinders being arranged in tandem, and a piston mounted in eachcyl inder, said pistons providing intermittent periods ofexhaust-pressure producing activity in the casing conduit, the combinedperiods of activity of the pistons providing a constant exhaust pressureon said conduit of substantially uniform degree.

t. An exhaust pump apparatus comprising a casing having a conduit,cylinder heads in said casing and each having a conduit in opencommunication with the casing conduit, a cylinder for each head, saidcylinders being arranged in tandem, said cylinders being free frominter-communication, each cylinder having valve-controlled communicationwith its head-conduit, and a motor-driven piston for each cylinder, eachpiston having valve mechanism to provide vacuum pressure within itscylinder, said pistons having movements of equal length and timed toprovide substantially non-concurrent intermittent periods ofexhaustpressure producing activity on said casingconduit.

5. An exhaust pump apparatus comprising a casing having a conduit,cylinder heads in said casing and each having a con duitin opencommunication with the casing conduit, a cylinder for each head, saidcylinders being arranged in tandem, said cylinders being free frominter-communication, each cylinder having valve-controlled communicationwith its head conduit, and a motor driven piston for each cylinder, eachpiston having valve mechanism to provide vacuum pressure within itscylinder, said pistons having movements of equal length and timed toprovide substantially non-concurrent intermittent periods ofexhaust-pressure producing activity on said casing-conduit, the combinedperiods of activity providing a constant exhaust-pressure on saidconduit of substantially uniform degree.

6. In combination, a chamber, a plurality of cylinders arranged intandem, said cylinders each having a head formed with a conduit in opencommunication with said chamber, each head having an opening leading toits cylinder, valves carried by said heads for controlling saidopenings, and a reciprocating piston mounted within each cylinder, thereciprocations of the pistons severally providing intermittent periodsof action on its head conduit, said pistons hav ing relative movementsto combinedly provide a constant action on the chamber of substantiallyuniform degree.

7. In combination, a chamber, a plurality of cylinders arranged intandem, said cylinders each having a head formed with a conduit in opencommunication with said chamber, each head having an opening leading toits cylinder, valves carried by said heads for cont-rolling saidopenings, and a reciprocating piston mounted within each cylinder, thereciprocations of the pistons severally providing intermittent periodsof action on its head conduit, said pistons having movements of uniformlength and timed to combinedly provide a constant action on the chamberof substantially uniform degree.

8. In combination, a casing having a conduit, cylinder heads each havinga conduit in open communication with the casing conduit, a cylinder foreach head and in controlled communication with the conduit in the head,said cylinders being arranged in tandem, and a piston mounted in eachcylinder, said pistons providing intermittent periods of activity in thecasing conduit, the combined periods of activity of the pistonsproviding a constant action on said conduit of substantially uniformdegree.

9. A pump apparatus comprising a casing having a conduit, cylinder headsin said casing and each having a conduit in open communication with thecasing conduit, a cylinder for each head, said cylinders being arrangedin tandem, said cylinders being free from inter communication, eachcylinder having valve-controlled communication with its head-conduit,and a motor-driven piston for each cylinder, each piston having valvemechanism to provide action within its cyl' inder, said pistons havingmovements of equal length and timed to provide substantiallynon-concurrent intermittent periods of activity on said casing-conduit.

10. A pump apparatus comprising a casing having a conduit, cylinderheads in said casing and each having a conduit in open communicationwith the casing conduit, a cylinder for each head, said cylinders beingarranged in tandem, said. cylinders being free from inter-communication,each cylinder having valve-controlled communication with itshead-conduit, and a motor-driven piston for each cylinder, each pistonhaving valve mechanism to provide action within its cylinder, saidpistons having movements of equal length and timed to providesubstantially non-concurrent intermittent periods of activity on saidcasing-conduit, the combined periods of activity providing a constantaction in said conduit of substantially uniform degree.

11. A pump comprising a plurality of hollow heads spaced one fromanother and arranged in tandem, a cylinder for each head, said cylindersbeing non-communicating, a valved port connecting each cylinder with itshead, a valved piston within each cylinder, a rotatable shaft, andindependent connections between the shaft and each piston, each headhaving a passageway leading to a chamber adapted to be affected bymovements of all of the pistons.

12. A pump comprising a plurality of cylinders in axial alinement andarranged in tandem, each cylinder having a hollow head, a valved portconnecting each cylinder with its hollow head, a piston within eachcylinder, a rotatable shaft, independent connections between said shaftand each piston, a port in each cylinder and open to the atmosphere, anda controlling valve common to all of said ports.

18. A pump comprising a plurality of cylinders in axial alinement andarranged in tandem, each cylinder having a hollow head, a valved portconnecting each cylinder with its hollow head, a piston within eachcylinder, a rotatable shaft, independent connections between said shaftand each piston, and a conduit open to and connecting the spaces of saidhollow heads.

14. A pump comprising a hollow casing having a plurality of hollow headsin communication therewith and arranged in axial alinement, a tubularcasing for each head, said latter casings each forming a cylinder, saidcylinders being of less length than the distance between the adjacentheads, a valved port connecting each head with its cylinder, saidcylinders being free from inter-communication, a piston for eachcylinder, a driven shaft, and independent connections between said shaftand each piston.

15. A pump comprising a hollow casing having a plurality of hollow headsin communication therewith and arranged in axial alinement, a tubularcasing for each head, said latter casings each forming a cylinder, eachcylinder having an open end, said cylinders being of less length thanthe distance between adjacent heads, a valved port connecting each headwith its cylinder, said cylinders being free from inter-connnunication,a piston for each cylinder, a driven shaft, and independent connectionsbetween said shaft and each piston, said connections extending throughthe open end of the cylinders.

16. A pump comprising a hollow casing having a plurality of hollow headsin communication therewith and arranged in axial alinement, each headhaving a port and also having a screw-threaded boss, a tubular casingscrew-threaded on each of said bosses and adapted to form a cylinder oneach head, said cylinders being of a length less than the distancebetween adjacent heads and each having an open end, a valve forcontrolling each head port, a piston in each cylinder, said cylindersbeing free from inter-communication, a driven shaft, and independentconnections between said shaft and said pistons.

In testimony whereof I have hereunto set my hand in presence of twosubscribing wit- GEORGE S. WILLIAMS. Witnesses:

J. GRANVILLE MnYnRs, T. L. VAUGHAN.

nesses.

